Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Geochronological evidence supporting Antarctic deglaciation three million years ago


THE response of the Antarctic ice sheets to increased global temperatures is an important unresolved issue in the assessment of future climate change. In particular, considerable controversy exists as to whether the East Antarctic ice sheet suffered extensive deglaciation during the mid-Pliocene epoch (3 Myr ago), when temperatures were only slightly warmer than today. Although the ice sheet is widely assumed to have existed in something like its present form for the past 14 Myr (ref. 1), marine diatoms eroded from the Antarctic interior have been found in glacial till deposits high in the Transantarctic Mountains2,3, and have been bio-stratigraphically dated at 3 Myr before present. This age has been disputed4 because it implies marine deposition in the Antarctic interior, and hence substantial deglaciation, at a time when other evidence has been marshalled for the persistence of cold, polar conditions4. Here we report K–Ar and 40Ar/<39 Ar ages for a volcanic ash bed in diatom-bearing glaciomarine strata cored in Ferrar Fiord (East Antarctica) by the CIROS-2 drill-hole5, which confirm the age of the diatoms at 3 Myr, and hence also confirm the mid-Pliocene deglaciation.

This is a preview of subscription content, access via your institution

Relevant articles

Open Access articles citing this article.

Access options

Rent or buy this article

Get just this article for as long as you need it


Prices may be subject to local taxes which are calculated during checkout


  1. Kennett, J. P. Marine Geology (Prentice-Hall, Englewood Cliffs, New Jersey, 1982).

    Google Scholar 

  2. Webb, P. N., Harwood, D. M., McKelvey, B. C., Mercer, J. H. & Stott, L. D. Geology 12, 287–291 (1984).

    Article  ADS  Google Scholar 

  3. Webb, P. N. & Harwood, D. M. Quat. Sci. Rev. 10, 215–223 (1991).

    Article  ADS  Google Scholar 

  4. Clapperton, C. M. & Sugden, D. E. Quat. Sci. Rev. 9, 253–272 (1990).

    Article  ADS  Google Scholar 

  5. Pyne, A. R., Robinson, P. H. & Barrett, P. J. Antarctic Data Ser. 11 (Res. School Earth Sci., Victoria Univ., Wellington, 1985).

    Google Scholar 

  6. Shackleton, N. J. & Kennett, J. P. in Init. Rep. DSDP 29 (eds Kennett, J. P. & Houtz, R. E.) 743–756 (U.S. Govt Printing Office, Washington DC, 1975).

    Google Scholar 

  7. Kennett, J. P. & Shackleton, N. J. Nature 260, 513–515 (1976).

    Article  ADS  CAS  Google Scholar 

  8. Marchant, D. R., Lux, D. R., Swisher, C. C. III & Denton, G. H. Antarct. J. U.S. 25, 58–59 (1990).

    Google Scholar 

  9. Webb, P. N. J. foram. Res. 4, 188–199 (1974).

    Article  Google Scholar 

  10. Webb, P. N. & Wrenn, J. in Antarctic Geoscience (ed. Craddock, J. C.) 1117–1122 (Univ. of Wisconsin Press, Madison, 1982).

    Google Scholar 

  11. Ishman, S. E. & Webb, P. N. Rev. Paleobiol. Spec. Vol. 2, Pt 2, 523–551 (1988).

  12. Kyle, P. R. in Dry Valley Drilling Project, Am. geophys. Un. Antarct. Res. Series 33 (ed. McGinnis, L. D.) 403–412 (1981).

    Book  Google Scholar 

  13. Webb, P. N. & Andreasen, J. Antarct. J. U.S. 21, 59–61 (1986).

    Google Scholar 

  14. Harwood, D. M. thesis, Ohio State Univ. (1986).

  15. Ciesielski, P. F. Init. Rep. DSDP 71 (eds Ludwig, W. J. et al.) (U.S. Govt Printing Office, Washington DC, 1983).

    Google Scholar 

  16. Burckle, L. H., Gayley, R. I., Ram, M. & Petit, J.-R. Geology 16, 326–329 (1988).

    Article  ADS  Google Scholar 

  17. Harwood, D. M. et al. in Proc. ODP, Scient. Results 120 (eds Wise, S. W. Jr et al.) 813–848, (Ocean Drilling Program, College Station, Texas, 1992).

    Google Scholar 

  18. McKelvey, B. C., Webb, P. N., Harwood, D. M. & Mabin, M. C. G. in Geological Evolution of Antarctica (eds Thomson, M. R. A., Crame, J. A. & Thomson, J. W.) 675–682 (Cambridge Univ. Press, Cambridge, 1991)

    Google Scholar 

  19. Mayewski, P. A. & Goldthwait, R. P. Am. geophys. Un. Antarct. Research Ser 36, 275–324 (1985).

    Article  Google Scholar 

  20. Denton, G. H., Hughes, T. & Burckle, L. H. in Geology of Antarctica (ed. Tingey, R. J.) 365–419 (Clarendon, Oxford, 1991).

    Google Scholar 

  21. Burckle, L. H. & Pokras, E. M. Antarct. Sci. 3, 389–403 (1991).

    Article  ADS  Google Scholar 

  22. Barrett, P. J. & Hambrey, M. J. Sedimentology 39, 109–123 (1992).

    Article  ADS  Google Scholar 

  23. Le Bas, M. J., Le Maitre, R. W., Streckeisen, A. & Zanettin, B. J. Petrology 27, 745–750 (1986).

    Article  ADS  CAS  Google Scholar 

  24. Warren, G. in Antarct. Map Folio Ser. (eds Bushnell, V. C. & Craddock, C.) Folio 12, Geology Sheet 14 (Am. geogr. Soc., New York, 1970).

    Google Scholar 

  25. Swisher, C. C. & Prothero, D. R. Science 249, 760–762 (1990).

    Article  ADS  CAS  Google Scholar 

  26. Lo Bello, P., Fraud, G., Hall, C. M., York, D., Lavina, P. & Bernat, M. Chem Geol. 66, 61–71 (1987).

    CAS  Google Scholar 

  27. Fleck, R. J., Sutter, J. F. & Elliot, D. H. Geochim. cosmochim. Acta 41, 15–32 (1977).

    Article  ADS  CAS  Google Scholar 

  28. Hill, R. S., Harwood, D. M. & Webb, P. N. 8th Gondwana Symp., Hobart, Australia (abstr.) (1991).

  29. Barrett, P. J. in Antarctica and Global Climate Change (eds Harris, C. & Stonehouse, B.) 35–50 (Belhaven, Cambridge, 1991).

    Google Scholar 

  30. Behrendt, J. C. & Cooper, A. K. Geology 19, 315–319 (1991).

    Article  ADS  Google Scholar 

  31. Adams, C. J. N.Z. J. Geol. Geophys. 18, 443–467 (1965).

    Article  Google Scholar 

Download references

Author information

Authors and Affiliations


Rights and permissions

Reprints and Permissions

About this article

Cite this article

Barrett, P., Adams, C., Mclntosh, W. et al. Geochronological evidence supporting Antarctic deglaciation three million years ago. Nature 359, 816–818 (1992).

Download citation

  • Received:

  • Accepted:

  • Issue Date:

  • DOI:

This article is cited by


By submitting a comment you agree to abide by our Terms and Community Guidelines. If you find something abusive or that does not comply with our terms or guidelines please flag it as inappropriate.


Quick links

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing